1. Field
Embodiments of the present disclosure generally relate to apparatuses and methods for lithographic patterning and more particularly for lithographic patterning for large substrates subjected to yaw and positioning errors.
2. Description of the Related Art
Large area substrates are often utilized in the manufacture of liquid crystal displays (LCDs). LCDs or flat panels are commonly used for active matrix displays such as computers, touch panel devices, personal digital assistances (PDAs), cell phones, television monitors, and the like. Generally, flat panels may comprise a layer of liquid crystal material forming pixels sandwiched between two plates. When power from the power supply is applied across the liquid crystal material, an amount of light passing through the liquid crystal material may be controlled at pixel locations enabling images to be generated.
Microlithography techniques are generally employed to create electrical features incorporated as part of the liquid crystal material layer forming the pixels. According to this technique, a light-sensitive photoresist is typically applied to at least one surface of the substrate. Then, either a photolithography mask or pattern generator exposes selected areas of the light-sensitive photoresist as part of a pattern with light to cause chemical changes to the photoresist in the selective areas to prepare these selective areas for subsequent material removal and/or material addition processes to create the electrical features. The precise placement of the electrical features upon the substrate as part of the flat panel helps determine the quality of resultant image generated by the flat panel as a uniform distribution of the pixels formed by the electrical interconnections is desirable to correctly reproduce the images viewed by users.
As the sizes of substrates continues to grow in the flat panel display industry with every subsequent generation, precise placements of patterns across larger distances of the substrates using photolithography masks has become increasingly more challenging as both the lithography masks and substrates undergo distortions during operations resulting in pattern placement errors. Also, for large substrates, small changes in yaw may cause substantial positional errors on edges of a flat panel. Also for large substrates, a mechanical precision of conventional X-Y stages which support large substrates may not be sufficient to control the patterning placement error. Therefore, new apparatuses and approaches are needed to precisely and cost effectively create patterns on large substrates.